This invention relates to display devices of the type in which relative movement between an observer and the display presents successive frames of a moving image by virtue of directional properties of an image carrier forming part of the display device. The invention relates in particular, but not exclusively, to display devices comprising large scale advertising hoardings formed from a set of panels, and wherein the image carrier displaying the moving image comprises a lenticular member having a plurality of lenticular lenses which overlay an image hearing member upon which inter-digitated image elements are formed. Examples of such lenticular media are described in U.S. Pat. No. 5,699,190 and U.S. Pat. No. 5,959,718 and are commercially marketed by Eastman Kodak (Trade Mark) as Dynamic Imaging materials.
It is known to provide an advertising hoarding formed of a number of panels in which an image carrier is mounted on a single one of the panels and defines a moving image by virtue of the directional properties of the image carrier. Such displays are effective in attracting the attention of pedestrians and travellers in moving vehicles, the moving image typically being formed by animated photographic or graphics techniques or by use of actual events captured using a cine-camera or video camera.
Typically in such advertising hoardings the image carrier on the single panel providing the moving image is accompanied by a series of fixed image panels carrying text or other fixed images not having directional properties to complete the advertising message. Typically, the entire hoarding cannot practically be formed of a single image carrier having directional properties because of cost and the technical implications of introducing a single large scale lenticular image medium.
The present invention seeks to provide an improvement whereby more than one of the panels of the display may comprise an image carrier providing part of the same moving image. A problem anticipated with such composite displays is that the panels will generally be required to extend in a planar array, as for example along the side of a building, and the observer will observe the display at a distance which is determined by local topography such as the locations of a pavement, pathway or traffic lane. If for example more than one identical image carriers are simply mounted against the wall of the building in co-planar relationship and spaced apart in the direction of observer travel, the portions of moving image which the respective panels provide will not in general be simultaneously viewable from the same direction and therefore will not be in sync.
According to the present invention, a composite display is formed by a set of image carriers displaying multiple frames which are selectively viewable depending upon viewing direction and wherein the image carriers are supported such that their orientations can be adjusted. The image carriers each include at least one frame recognisable as being a reference frame so that during an on-site alignment procedure the image carriers can be adjusted in orientation such that the reference frames of each image carrier are simultaneously viewable by an observer at an alignment position. This ensures that the frames of the moving image provided by each image carrier are in sync with the frames of the moving image provided by the other image carriers of the set.
A further aspect of the invention provides image carriers for which the viewing angle corresponding to the reference frame is determined during a manufacturing process according to the position which the image carrier will adopt when assembled into the array of image carriers forming the composite display, thereby minimising the need for adjustment in orientation during the onsite alignment procedure. Typically therefore, image carriers which are to be located at an array position at the centre of the composite display may have a viewing angle for the reference frame which is at or about 90xc2x0 relative to the planar extent of the image carrier whereas those image carriers which are intended to be located at the periphery of the composite image may have a viewing angle which is less than 90xc2x0.
During the onsite alignment procedure, it is necessary for the reference frame to be readily recognised by operatives performing the alignment and therefore a further aspect of the invention relates to providing means for recognising the reference frames such as by the inclusion in the reference frame image of indicia such as a symbol. In the preferred embodiment, the symbols are square markers, such symbol being placed at suitable locations in the image frame so as not to obscure the image information.